In most homes and buildings, turning on and off lights, lamps, or other devices is accomplished by toggling a switch that is wired into the building's electrical system. This paradigm requires the location of the lighting, fixtures, switches, and devices to be based on the location of the physical wires installed by licensed electricians, typically during initial construction. If there is a desire to relocate or any of the devices or to alter how the devices are controlled, there is no practical means to do so without moving and/or running additional fixed power wires.
The difficulties associated with adding on to or altering a structure's electrical system presents a number of inconveniences and costs to the building occupant. First, the locations of the fixtures and switches are established by the builder, not the occupant. Over time, usage changes and successive occupants need different configurations other than those envisioned by the builder. Second, moving fixtures and wiring is costly and disruptive. It requires construction professionals to relocate wires by tearing into walls and ceilings and then repairing and repainting entire rooms in order to mask the changes.